Thermally matched fluid cooled power converter

ABSTRACT

A thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. Power electronic circuits are thermally matched, such as between component layers and between the circuits and the support. The support may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. ProvisionalApplication No. 60/349,259, filed Jan. 16, 2002.

GOVERNMENT LICENSE RIGHTS

[0002] This invention was made with Government support under CooperativeAgreement No. DE-FC02-99EE50571 awarded by the Department of Energy. TheGovernment has certain rights in this invention.

BACKGROUND OF THE INVENTION

[0003] The present technique relates to power electronic devices andtheir incorporation into modules and systems. More particularly, thetechnique relates to the configuration, packaging and thermal matchingwithin of power electronic devices and supports within modular powerconverters.

[0004] A wide array of applications are known for power electronicdevices, such as power switches, transistors, and the like. For example,in industrial applications, silicon controlled rectifiers (SCRs),insulated gate bipolar transistors (IGBTs), field effect transistors(FETs), and so forth are used to provide power to loads. In certainapplications, for example, arrays of power switches are employed toconvert direct current power to alternating current waveforms forapplication to loads. Such applications include motor drives. However,many more applications exist for inverter circuitry and other circuitryincorporating such devices. Other settings include electric vehicleapplications grid tie inverters, DC to DC converters, AC to AC powerConverters, and many other solid state power conversion elements thatrequire a packaged power device switch topology. In electric vehicles, asource of direct current is typically available from a battery or powersupply system incorporating a battery or other direct or rotating energyconverter. Power electronic devices are employed to convert this powerto alternating current waveforms for driving one or more electricmotors. The motors serve to drive power transmission elements to propelthe vehicle. While numerous constraints exist in such settings whichdiffer from those of industrial settings, numerous problems anddifficulties are shared in all such applications.

[0005] Demands made on power electronic devices typically include theirreliability, power output, size and weight limits, and requirementsregarding the environmental conditions under which they must operate.Where size and weight constraints force reductions in the packagingdimensions, difficulties arise in appropriately placing the powerelectronic devices, and drive and control circuitry associated with thedevices to sufficiently remove heat generated during their operation.Where size, cost and weight are less important, large heat sinks andheat dissipation devices may be employed utilizing any fluid that can beaccommodated by choice of materials that are compatible. However, aspackaging sizes are reduced, more efficient and effective techniques areneeded. Electrical and electronic constraints also impose difficultieson package design. For example, reduction of inductance in the circuitsand circuit layout is commonly a goal, while solutions for reducinginductance may be difficult to realize. Shielding from electromagneticinterference originating both within the package and outside the packagemay be important, depending upon the surrounding environment. Similarly,appropriate interfacing with external circuitry, and the facility toinstall, service and replace power electronics packages may be importantin certain applications. It has typically been necessary in manyinstances to configure the power electronic element to match closely thespecific needs of the application and by doing so meet cost, size,performance targets that can be achieved by no other means. Finally,certain environments, such as vehicle environments, impose a wide rangeof difficult operating conditions, including large temperature spans,vibration and shock loading, and so forth.

[0006] A particular problem arising in power electronics circuitry, andparticularly in converting circuitry arises from differential thermalexpansion and contraction between various circuit components. Becauseextremes in environmental and enclosure temperatures, significantlydifferent rates of expansion and contraction may arise within the powerelectronics circuits and within supporting structures. In suchcircumstances, delamination, deterioration, and malfunction can arisedue to repeated thermal cycles and the consequent expansion andcontraction. A particular challenge arises in cooling such circuitry,while preventing the degradation of the packaging and circuitry due tothe thermal expansion and contraction.

[0007] There is a need, therefore, for improved techniques in packagingof power electronic devices. There is a particular need for techniqueswhich offer good thermal management while addressing the issue ofdifferential thermal expansion and contraction.

SUMMARY OF THE INVENTION

[0008] The present technique provides power electronics modules designedto respond to such needs. The technique makes use of novel packaging,thermal management, interconnect, and grounding shielding approacheswhich both improve performance, and offer smaller, lighter and moreefficient configurations of the power electronic devices and their drivecircuitry. The technique offers multiple facets for such packaging andthermal management which can be adapted to a variety of settings,including industrial power electronics applications, vehicularapplications, and so forth. Many of the embodiments of the presenttechnique permit utilization of standardized cells designed to bereconfigured into a number of optimum configurations matching keyapplication requirements.

[0009] The features of the technique offer modular packaging, such asaround a thermal management system, generally including a thermalsupport and thermal matching between circuitry and the support, andwithin the circuitry (i.e. between component layers). Power electronicdevices may be mounted directly to the support for removal of heat. Thearrangement of the devices, and their interconnection with incoming andoutgoing power conductors may vary, and may make use of the thermalsupport for extraction of heat and for mounting of various components. Anumber of improved power device assemblies, their attachment means tothe thermal support are accommodated with the scope of the presenttechnique.

[0010] In an exemplary embodiment, and modular power converter isfeatured, although other types of power electronic circuitry may beadapted in the package. Incoming power conductors interface with theconverter circuitry, which converts the incoming power to desired outputpower, such as alternating current waveforms. The incoming and outgoingpower conductor configurations and arrangements may facilitateinstallation of the module into enclosures or vehicular mounting spaces,with plug-in connections being offered for both power and control.Coolant may be routed through the thermal support via additionalconnections. Exemplary coolant configurations are envisaged thateffectively extract heat by close and thermally matched mounting ofpower electronics and other electronic devices immediately adjacent toheat removal surfaces. Locations, positioning and interconnection ofcontrol, drive, and power electronic circuitry facilitate closepackaging of these elements. Shielding from electromagnetic interferencemay be facilitated through the use of the thermal support and, wheredesired, additional external shielding and closures. Optimum powerdevice temperature regulation means may be accommodated in the intrinsicfeatures of the thermal support such that they work in close harmonywith electrical power switching elements or other circuitry and theirthermomechanical attachment to both the inputs, outputs and the thermalsystem.

[0011] The present technique offers a wide range of improvements inpower electronics packaging and management. The improvements reside bothin the particular configuration of the packages, the configuration ofthe package components and the interrelationship and layout of thecomponents, their interfaces, and their operational interdependence. Thetechnique also offers more effective shielding from EMI/RFI. Moreover,better high frequency grounds may be achieved by low inductanceconnection means integrated into the thermal support. Connections may becooled by means of integrated bus structure in contact with electricallyinsulating but thermally conductive features in or integrated with thethermal support and coolant circulating system.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The foregoing and other advantages and features of the inventionwill become apparent upon reading the following detailed description andupon reference to the drawings in which:

[0013]FIG. 1 is a diagrammatical representation of a power electronicsmodule in accordance with certain aspects of the present technique;

[0014]FIG. 2 is a diagrammatical representation of a variation of themodule of FIG. 1 including additional circuitry supported on a thermalbase;

[0015]FIG. 3 is a further diagrammatical representation of a powerelectronics module having power electronic devices mounted to two sidesof a thermal base;

[0016]FIG. 4 is a diagrammatical representation of a power electronicsmodule having multiple thermal bases;

[0017]FIG. 5 is a block diagram of certain functional circuitry in anexemplary application of a power electronics module in accordance withaspects of the present technique for a vehicle drive;

[0018]FIG. 6 is a diagram of a power electronics module in accordancewith aspects of the present technique employed in an enclosure, such asin a vehicle or industrial setting;

[0019]FIGS. 7A and 7B are block diagrams of functional circuitry whichmay be supported in a package in accordance with the present techniques,including an inverter drive and a converter drive;

[0020]FIG. 8 is an exploded perspective view of an exemplary powerelectronics module and its associated packaging components;

[0021]FIG. 9 is a perspective view of the external interfaces of anexemplary package module of the type illustrated in FIG. 8, withslightly different interface connections;

[0022]FIG. 10 is a perspective view of the package module of FIG. 9illustrating additional interfaces on a rear side of the module package;

[0023]FIG. 11 is a perspective view of the package of FIG. 10 with ahousing cover removed to display internal arrangements of powerelectronics and associated circuitry and components;

[0024]FIG. 12 is a perspective view of the internal power module asshown in FIG. 11 with the module removed from the base housing;

[0025]FIG. 13 is an exploded perspective view of the arrangement of FIG.12 with control and drive circuitry removed;

[0026]FIG. 14 is a perspective view of a thermal base and powerelectronics substrate and device subassembly of the type employed in thearrangement of FIG. 13;

[0027] FIGS. 15A-1 5R are diagrammatical detail views of exemplaryarrangements for mounting and removal of heat from the power electronicssubstrate and thermal base;

[0028]FIG. 16 is an exploded perspective view of one arrangement forproviding a switch frame on a thermal base where the switch frame isremovable from the base;

[0029]FIG. 17 is a perspective view of a substrate for use with athermal base and illustrating an exemplary layout of power electronicsdevice subassemblies on the substrate;

[0030]FIG. 18 is an exploded perspective view of one of the exemplarydevice subassemblies shown in FIG. 17 and a preferred manner of formingthe device subassembly on the substrate;

[0031]FIGS. 19A and 19B are perspective view of an exemplary terminalstrip employed with a thermal base for routing incoming and outgoingpower to power electronic devices and their associated circuitry;

[0032]FIG. 20 is a diagrammatical representation of a preferred layoutof terminals and conductors in a terminal strip of the type illustratedin FIG. 19;

[0033]FIG. 21 is a circuit diagram illustrating the signal flow offeredthrough the layout of FIG. 20;

[0034] FIGS. 22A-22F are diagrammatical perspective views of anexemplary power electronics module illustrating various possible routingorientations for incoming power, outgoing power, and coolant;

[0035]FIG. 23 is a perspective view of an exemplary connector interfacefor use in a power electronics module in accordance with aspects of thepresent technique;

[0036]FIG. 24 is a perspective view of an alternative connectorinterface arrangement designed to achieve various orientations of thetype illustrated in FIG. 22;

[0037]FIG. 25 is a perspective view of an alternative configuration forpower electronics module wherein a canister is provided for mounting andshielding of the module components;

[0038]FIG. 26 is a perspective view of the elements of FIG. 25 aftermounting an assembly;

[0039] FIGS. 27A-27D are diagrammatical representations of alternativeterminal and terminal assembly connection arrangements for use in amodule in accordance with the present technique;

[0040] FIGS. 28A-28D are diagrammatical representations of alternativeterminal and terminal assembly cooling arrangements for use in a modulein accordance with the present technique;

[0041]FIGS. 29A and 29B are diagrammatical representations ofalternative terminal and plug configurations for EMI shielding andgrounding for a module in accordance with the present technique;

[0042] FIGS. 30A-30C are diagrammatical representations of alternativepower electronics substrate mounting arrangements for interfacing withheat removal structures in the module;

[0043]FIG. 31A is a diagrammatical prospective view of an alternativepower and control low inductance shield and ground arrangement for usein the module, while FIG. 31B is an exploded perspective view of anexemplary implementation of such an arrangement;

[0044]FIG. 32A is a diagrammatical elevational view of an alternativeplug-in module arrangement based upon the modules such as thoseillustrated in the previous Figures, while FIG. 32B is a perspectiveview of an exemplary implementation of the plug-in module arrangement;

[0045]FIG. 33 is a further alternative plug-in arrangement incorporatingsuch modules;

[0046]FIG. 34 is a diagrammatical representation of a module of the typeillustrated in the previous Figures incorporating flow control circuitryfor regulating the flow of coolant into and from the module;

[0047] FIGS. 35A-35C are diagrammatical views of circuits and physicallayouts of components for a converter arrangement employing aspects ofthe present technique;

[0048] FIGS. 36A-36C are diagrammatical views of circuits and physicallayouts of components for a matrix switch topology implementation ofaspects of the present technique;

[0049]FIG. 37 is a further diagrammatical view of a circuit inaccordance with the passing technique adapted for supply of power for amid-frequency welding application; and

[0050]FIGS. 38A and 38B are exemplary configurations of modules adaptedfor cooling of circuitry through indirect conduction to the thermalsupport.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0051] Before detailing specific embodiments of the inventive techniqueas presently contemplated, certain definitional notes are in order.Firstly, reference is made in the present disclosure to power devicesand subassemblies incorporating such devices. Such devices may include arange of components, such as power electronic switches (e.g. IGBTs,FETs) of various power ratings. The devices may also include gate drivercircuitry for such components, sensing and monitoring circuitry,protection circuitry, filtering circuitry, and so forth. The devices maybe provided in the subassemblies in various groupings, both integrallyand separate from supporting substrates and/or thermal expansioncoefficient members and heat transfer elements. Reference is also madeherein to energy storage and conditioning circuitry. Such circuitry mayvary in composition depending upon the particular configuration of theassociated power electronic devices and circuits. For example, ininverter drive applications as discussed below, the energy storage andconditioning circuitry may include one or more capacitors,capacitor/inductor circuits or networks. Filtering circuitry may also beincluded for signal conditioning. In other applications, such as mediumfrequency welding, the energy storage and conditioning circuitry mayinclude one or more transformers. Finally, while reference is madeherein to a thermal support used in conjunction with power devices andother circuitry, various configurations and functions may be attributedto the support. For example, as described below, the support may provideboth mechanical and electrical support for the various components, aswell as offer integrated and highly efficient cooling of some or all ofthe components. Moreover, the support may provide electrical andshielding functions, such as for EMI and RFI shielding both of externalfields that may affect the components as well as fields that may begenerated by the components during operation. Thermal regulatingcomponents and circuits may also be incorporated into or associated withthe support.

[0052] Turning now to the drawings, and referring first to FIG. 1, anexemplary power electronics module 10 is illustrated. Module 10 includesa thermal support 12 on which power electronic circuit 14 is disposed.As described in greater detail below, thermal support 12 may include arange of thermal management features, such as porting for routing ofcoolant for extracting heat from circuit 14. Similarly, circuit 14 mayinclude a wide range of functional circuitry, such as invertercircuitry, converter circuitry, and so forth which is mounted on support12 for mechanical and electrical support, improved EMI/RFI shielding andhigh frequency grounding, as well as for extraction of heat generatedduring its operation. In the embodiment of FIG. 1, module 10 furtherincludes control and driver circuitry, designated generally by referencenumeral 16. Incoming power, as indicated by arrow 18 is applied tocircuitry 14 and outgoing power 20 is routed from the circuitry toexternal devices (not shown). Similarly, in the diagrammaticalrepresentation of FIG. 1, coolant 22 is applied to the thermal support12 to extract heat from the power electronic circuit 14 and from thethermal support, as well as from the control and driver circuitry 16.Outgoing coolant 24 is routed from the thermal support to carry heataway to a cooling system (not shown). In the embodiment of FIG. 1, boththe power electronic circuit 14 and the control and driver circuitry 16are mounted on a side 26 of the thermal support 12. Both incoming andoutgoing power are routed to the circuitry at an edge 28 of the thermalsupport. Finally, interconnections 32 are provided between the controland driver circuitry 16 and the power electronic circuit 14 for controlof operation of the circuitry as described more fully below.

[0053]FIG. 2 illustrates an exemplary alternative configuration of apower module 10 in which components are mounted on both sides of thethermal support. In the embodiment of FIG. 2, power electronic circuit14 is again mounted to side 26 of the thermal support 12. In theembodiment of FIG. 2, however, driver circuitry 34 for controllingfunctioning of the power electronic circuit is mounted to the same side26 of the thermal support, while control circuitry 36 is separated fromthe driver circuitry. Energy storage and conditioning circuitry, asindicated generally at reference numeral 38, is also mounted on thethermal base. As before, interconnections 32 between driver circuitry 34and power electronic circuit 14 are provided, as are similar connections40 between the control circuitry and the driver circuitry, andinterconnections 42 between the power electronic circuit 14 and theenergy storage and conditioning circuitry 38. As will be noted, in theembodiment of FIG. 2, the geometry, layout and space utilization of thethermal support are adapted such that the control circuitry 36 and theenergy storage and conditioning circuitry 38 are mounted on a lower side44 of the thermal support 12. All such components may therefore bemechanically and electrically supported on the thermal support, whilereceiving cooling via coolant flow as indicated by arrows 22 and 24.

[0054]FIG. 3 illustrates a further exemplary configuration of a module10 wherein power electronic circuits are mounted on both sides of thethermal support. Thus, as shown in FIG. 3, a thermal support 12 servesfor mechanical and electrical mounting of both power electronic circuit14, and control and a driver circuitry 16 with the necessaryinterconnections 32 being provided between these circuits. A secondpower electronic circuit 46, and second control and driver circuitry 48are provided on the opposite side of the thermal support 12 thus makingthe use of the cooling fluid nearly significantly more effective as itwould be with only one side of the heat exchanger used for activecooling. Thus, heat may be extracted from both power electronic circuitsbus work, input output terminals, energy storage elements and supportelectronics by virtue of coolant flow through or around the thermalsupport.

[0055]FIG. 4 illustrates a further exemplary configuration of a module10. In the exemplary configuration of FIG. 4, power electronic circuit14 is again mounted to a side of the thermal support 16 along withcontrol and driver circuitry 16. Energy storage and conditioningcircuitry 38 is mounted on an opposite side of the thermal support. Inthis alternative configuration, a second thermal support 50 is securedto the first thermal support 12, and itself supports additional energystorage and conditioning circuitry 38. As will be appreciated by thoseskilled in the art, the particular circuitry supported on the one ormore additional thermal supports may vary depending upon the systemneeds. Accordingly, capacitor circuitry, power electronic circuitry,driver circuitry, control circuitry, energy storage components,inductors, filters, braking resistors, and so forth, or any otherancillary circuitry may be provided on the additional thermal support.Moreover, in the embodiment of FIG. 4, coolant is routed separately tothe second thermal support 50. A modular system of stackinginterconnect, thermal connection, and support features may be providedsuch that thermal base, power terminal assemblies can interconnect inparallel and series combinations to form larger and differently ratedpower converters using the core thermal-electrical base described.Depending upon thermal management needs and available plumbing, however,coolant could be routed to one of the thermal supports alone, or coolantcould be routed internally between the thermal supports. Similarly,interconnection 52 made between the energy storage and conditioningcircuitry 38 of FIG. 4 could include a range of interconnections betweenfunctional circuitry, including power electronic circuits, and theirassociated drive and control circuits.

[0056] The exemplary configurations of FIGS. 1-4 can be adapted tosupport a wide range of functional power electronic circuits. FIGS. 5and 6 illustrate exemplary applications of the power electronicsmodules. In the illustration of FIG. 5, a vehicle drive 54 is provided,such as a drive for an automobile or other mobile application. Thevehicle drive 54, which may include the functional circuits of FIG. 5 aswell as a wide array of additional support, control, feedback and otherinterrelated components, will generally include a power supply 56 whichprovides the power needed for driving the vehicle. In a typicalapplication the power supply 56 may include one or more batteries,generators or alternators, fuel cells, utility source, alternators,voltage regulators, and so forth. Power supply 56 applies power,typically in the form of direct current via direct current conductors 58to the power electronics module 10. Control circuitry 60 providescontrol signals for regulating operation of the power electronicsmodule, such as for speed control, torque control, acceleration,braking, and so forth. Based upon such control signals, powerelectronics module 10 outputs alternating current waveforms along outputconductors, as indicated generally at reference numeral 20 in FIG. 5.The output power is then applied to a vehicle drive train as indicatedgenerally at reference numeral 62. As will appreciated by those skilledin the art, such drive trains will typically include one or morealternating current electric motors which are driven in rotation basedupon the frequency and power levels of the signals applied by the powerelectronics module 10. The vehicle drive train may also include powertransmission elements, shafts, gear trains, and the like, ultimatelydesigned to drive one or more output shafts 64 in rotation. Sensorcircuitry 66 is provided for sensing operating characteristics of boththe vehicle, the drive train, and the power electronics module. Thesensor circuitry 66 typically collects such signals and applies them tothe control circuitry, such as for regulation of speeds, torques, powerlevels, temperatures, flow rates of coolants, and the like.

[0057]FIG. 6 illustrates a further application of a power electronicsmodule 10 in an industrial or mobile setting. In an industrial setting,the power electronics module 10 may be applied for application of powerto various loads, such as electric motors, drives, valving, actuators,and so forth. In the system, designated generally by reference numeral68, an enclosure 70 is provided that may be divided into bays 72. Withineach bay various components are mounted and interconnected forregulating operation of processes, such as manufacturing, materialhandling, chemical processes, and the like. The components, designatedgenerally by reference numeral 74, are mounted within the bays andreceive power via an alternating current bus 76. A control network 78applies control signals for regulating operation of the components 74and of the power electronics module 10. An enclosure, such as enclosure70 may be included in various industrial settings, such as in motorcontrol centers, assembly line or process controls, and so forth.However, such enclosures may also be provided in a vehicular setting,such as for driving one or more drive trains of an automobile, utilityvehicle, transport or other vehicle.

[0058] As mentioned above, various circuit configurations may bedesigned into the power electronics module. The circuit configurationswill vary widely depending upon the particular requirements of eachindividual application. However, certain exemplary circuitconfigurations are presently envisaged, both of which include powerelectronic devices which require robust and compact packaging along withthermal management. Two such exemplary circuits are illustrated in FIGS.7A and 7B. In FIG. 7A, the circuitry includes a rectifier circuit 80which converts alternating current power from a bus 76 to direct currentpower for output along a DC bus, corresponding to incoming power lines18. An inverter circuit 82 receives the direct current power andconverts the direct current power to alternating current waveforms atdesired frequencies and amplitudes. The alternating current power maythen be applied to a load via the outgoing conductors 20. Filter andstorage circuitry 84 may be coupled across the direct current bus tosmooth and condition the power applied to the bus. A control circuit 86regulates operation of the rectifier and inverter circuits. In theexample of FIG. 7B, a direct and/or matrix converter 90 includes a setof AC switching power devices per phase of power controlled. Inverter 90receives incoming alternating current power and supplies an outgoingwaveform to power switches 88. The set of AC switches effectivelyconvert fixed frequency incoming power 18 to controlled frequencyoutgoing power 20 for application to a load. The arrangement of FIG. 7Bis illustrated in greater detail in FIG. 36C. It should be borne inmind, however, that the particular circuitry of FIGS. 7A and 7B areexemplary only, and any range of power electronic circuits may beadapted for incorporation into a module in accordance with the presenttechniques.

[0059]FIG. 8 illustrates an exemplary physical configuration for a powerelectronics module 10. In the embodiment of FIG. 8, a circuit assembly92 is positioned within a housing 94 and enclosed within the housing bya cover 96 fitted to the housing. Circuit assembly 92 includes thecomponents described above, and in the particular embodiment illustratedcorresponds generally to the configuration of FIG. 2. As illustrated,thus, the circuit assembly 92 includes a thermal support 12 on whichpower electronic circuit 14 is disposed. Control and driver circuitryare also disposed on the thermal support for regulating operation of thepower electronic circuit with cooling of such circuitry. In theembodiment of FIG. 8, the module is particularly configured foroperating as an inverter drive for a vehicle application. Incomingdirect current power is received via conductors 18, and converted tothree-phase waveforms output via conductors 20.

[0060] In the embodiment of FIG. 8, housing 94 presents a controlinterface 98 which is designed to permit control signals to be receivedwithin and transmitted from the housing. As described in greater detailbelow, the control interface may be provided on a bottom side of thehousing as illustrated in FIG. 8, or at other positions on the housing.A power interface, designated generally by reference numeral 100 in FIG.8, is provided for transmitting power to and from the circuit assembly92. As described below, various configurations can be provided and arepresently envisaged for interfacing the module 10 with externalcircuitry. In the embodiment of FIG. 8, for example, the power interface100 permits five conductors two direct current conductors and threealternating conductors, to be directly interfaced from the circuitassembly, such as in a plug-in arrangement. In addition to the controland power interfaces, a coolant interface 102 is provided for receivingand circulating coolant as described more fully below. In presentembodiments, the coolant interface may include tubes or specializedfittings adapted to receive conduits for channeling fluid to and fromthe module. It should be noted, however, that where appropriate,liquids, gases, compressed gases, and any other suitable cooling mediamay be employed in the present technique. Thus, while in vehicleapplications the combination of water and conventional vehicle coolantmay be used, other specialized or readily available cooling media may beemployed.

[0061] In the embodiment of FIG. 8, housing 94 forms a metallic shell,such as of aluminum, which is cast to provide shielding of EMI, bothgenerated by the module circuitry and which may be present in theenvironment of the module. Cover 96 is made of a similar material toprovide shielding on all sides of the module. As described below,connector interfaces may also provide additional shielding, and areparticularly useful in applications where high frequency waveforms aregenerated by the power electronic components, such as inverter drives.Where appropriate, other types of housings and supports may be employed.For example, where sufficient EMI shielding is provided, or where EMItransmissions are sufficiently reduced by proximity of the powerelectronic components to the thermal support, plastic housings, dopedplastic housings, and the like may be employed.

[0062] In the illustrated embodiment, housing 94 includes a cavity 104in which circuit assembly 92 is disposed. Conductors 106 transmit DCpower to the circuit assembly 92, while conductors 108 transmit the ACwaveforms from the circuit assembly 92 for application to a load. Aninterface plate 110 is provided through which conductors 106 and 108extend. Where desired, sensors may be incorporated into the assembly,such as current sensors 112 which are aligned about two of the outgoingpower conductors 108 to provide feedback regarding currents output bythe module. As will be appreciated by those skilled in the art, othertypes and numbers of sensors may be employed, and may be incorporatedboth within the housing, within a connector assembly, or within thecircuit assembly itself.

[0063] As described more fully below, thermal support 12 may incorporatea variety of features designed to improve support, both mechanical andelectrical, for the various components mounted thereon. Certain of thesefeatures may be incorporated directly into the thermal support, or maybe added, as is the case of the embodiment of FIG. 8. As shown in FIG.8, a frame 114, made of a non-metallic material in this embodiment, isfitted to the thermal support 12, and components mounted to the thermalsupport are at least partially surrounded by the frame. The frame servesboth as an interface for conductors 106 and 108, and for surroundingcircuitry supported on thermal support 12 to receive an insulating orpotting medium. In the embodiment of FIG. 8 terminals 116 are formed onframe 114, and may be embedded within the frame during molding of theframe from an insulative material. A preferred configuration for theterminals is described more fully below. Separators 118 partiallysurround terminals 116 for isolating the conductors coupled to theterminals from one another.

[0064] An alternative configuration for the housing 94 and cover 96 ofthe module is illustrated in FIGS. 9 and 10. As shown in FIG. 9, thehousing may provide for interfaces for power conductors at differentlocations, such as along topside as illustrated in FIG. 9 for incomingpower, and along an edge for outgoing power. Accordingly, an incomingpower interface 120 may be specifically adapted to provide connectionsto conductors 106, such as from a DC power source. An outgoing powerinterface 122 may provide similar connections for conductors 108 used totransmit controlled AC waveforms to a load. As will appreciated, theinterfaces may be provided either in the housing itself or in the cover,or both. The coolant interface 102 may be similarly provided at variouslocations about the housing and cover, such as along an edge as shown inFIG. 9.

[0065]FIG. 10 is a rear prospective or the arrangement of FIG. 9. Asshown in FIG. 10, the control interface 98 may be available from variouslocations on the housing and cover. In the embodiment of FIG. 10 amulti-pin connector 124 is provided for receiving a control cable. Pindesignations for the connection may follow any suitable protocol, and ina present embodiment may include pins designated for transmission to anRS232 or other serial or parallel data transmission port. Once closed,the housing and cover may define a water-tight, EMI-shielded packagewithin which the circuit assembly is positioned. Moreover, the packagingmay include any suitable handles, tool geometries, and the like forplugging the module into an application, or for otherwise supporting themodule in an application. For example, where a handle (not shown) isprovided on the package, the handle may be grasped by a user to simplyplug the module into a mating interface, such as within a vehicle orenclosure.

[0066]FIG. 11 illustrates certain internal configurations of theembodiment of FIGS. 9 and 10 with cover 96 removed. As shown in FIG. 11,the module 10 comprises the housing 94 in which the circuit assembly 92is disposed. Conductors 108, separated by an interface plate 110 fromthe surrounding environment, are available for connection within powerinterface 122. A similar power interface may be provided, as illustratedin FIG. 9, for other power conductors. The control interface 98 ispositioned on an opposite side of the housing in the embodiment of FIG.11, and supports multi-pin connection 124.

[0067] In the arrangement of FIG. 11, an integral flange 126 is formedon the thermal support 12 and extends generally upwardly from the planeof the thermal support, partially replacing the removable frameillustrated in FIG. 8. The integral flange serves to support andinterface the circuit assembly 92 within the housing (such as by matingwith the cover where desired), and surrounds certain of the circuitry,such as to form a cavity 128 within which the circuitry is mounted andwithin which an insulating or potting medium may be disposed. Powerelectronic device subassemblies 130 are provided within the cavity, andform the power electronic circuits 14 as described more fully below. Inthe illustrated embodiment, six such device subassemblies or switchingcircuits are provided for defining a three-phase inverter circuit. Aswill be appreciated by those skilled in the art, in practice, two ormore such switching circuits may be grouped on each device subassembly,or entire set of circuits may be provided in a single devicesubassembly. Connection pads 132 are provided adjacent to devicesubassemblies 130 for interfacing the device subassemblies with incomingand outgoing power conductors. In the illustrated embodiment, a terminalstrip 134, described in greater detail below, is provided at an edge ofthe thermal support 12, and mates with the integral flange 126 to definethe cavity within which the circuitry is disposed and within which apotting medium may be placed. The terminal strip may include molded-endfeatures, including the connection pads 132, as well as terminals andconductors as described below.

[0068] Within the housing, various other features may facilitateinterconnections between the various circuits and components. Forexample, in the illustrated embodiment sensor cabling 136 is providedfor receiving signals from current sensors 112. Such signals may berouted, via the cabling 136 around the housing to drive circuitry 34 orcontrol circuitry 36, so as to monitor operating conditions of the powerelectronic circuitry. Other types of sensors and placements of suchsensors, along with signal transmission cabling may, of course, beincorporated in the arrangement.

[0069]FIG. 12 illustrates the circuit assembly 92 of FIG. 11 removedfrom housing 94. Again, in the illustrated embodiment the thermalsupport 12 is provided with an integral flange 26 which partiallysurrounds the power electronic circuit 14. In the illustratedembodiment, the driver circuitry 34 for the device subassemblies 130 isalso provided within the cavity defined by flange 126. The drivercircuitry 34 and the control circuitry 36 may be provided on a singleprinted circuit board or on two or more boards, and may define asingle-sided board component arrangement or double sided arrangement.Where a double-sided board is provided, spacers, standoffs, or similararrangements may be provided for insuring that an insulating or pottingmaterial may be provided between the board and the thermal support.

[0070] Returning to FIG. 11, to provide the desired sealing, aperipheral edge 138 may be provided on the housing and cover, with agroove 140, or other interface feature, provided for receiving a seal, asealing compound or the like. As shown in both FIGS. 11 and 12, whileone or more of the circuits may be provided on a top or bottom side ofthe thermal support as described above, in the present embodiment, arear board support 142 is provided as an integral feature of the thermalsupport 12. Thus, the control circuitry 36 may be supported on the rearboard support 142 and interfaced directly with the driver circuitry viainterconnections 40. These features of the present arrangement are bestillustrated in FIG. 13, where the drive circuitry 34 and controlcircuitry 36 have been exploded from the thermal support to illustratethe manner in which they may be disposed and interconnected along withcabling 136 from sensors 112. As also shown in FIG. 13, housings 144 maybe incorporated in the design, such as to support sensors 112.

[0071] A variety of interface configurations may be envisaged formounting the various components on the thermal support 12. In theembodiment illustrated in FIG. 13, for example, an energy storage andconditioning circuitry package 38 is enclosed in a housing 146 which ismounted directly to a lower side of the thermal support 12. Capacitorswithin the housing 146 are interconnected with the power electroniccircuitry as described more fully below. As also shown in FIG. 13, aninterface plate 148 is secured to the thermal support 12 and the powerelectronic device subassemblies 130 are disposed directly on theinterface plate 148. Thus, in accordance with aspects of the presenttechnique, the device subassemblies may be formed directly on andprocessed on the interface plate 148 which is later secured to thethermal support 12. Special processing, therefore, of the componentsmaking up device subassemblies 130 is facilitated by separatelyprocessing the device subassemblies and interface plate 148, and laterassembling the interface plate with the thermal support. FIG. 13 alsoshows an exemplary connection sensor 113 coupled to cabling 136 fordetecting whether appropriate connections have been made to the module(e.g., to prevent operation until such connections are completed), asdescribed below.

[0072] As illustrated in FIG. 14, the interface plate 148 is assembledwith the thermal support 12 in a present embodiment. Various securementfeatures or pads may be provided on the thermal support 12, such asindicated at reference numeral 150 in FIG. 14. The pads providelocations at which the thermal support may be secured within a housingof the type described above, or another mechanical structure. Thethermal support itself is preferably made of a conductive metal, such asaluminum. The support may be formed in any suitable manner, such as byassembly, machining, or, as in a present embodiment, by casting followedby certain machining operations. The support includes features whichfacilitate circulation of coolant for extracting heat from the powerelectronic circuit 14. In the embodiment of FIG. 14, these featuresinclude a trough or channel 152 formed within the thermal support. Thechannel extends between the coolant inlet 22 and the coolant outlet 24for the circulation of coolant. The channel preferably extends at leastalong an area of the interface plate 148 to remove sufficient heat fromthe circuitry during operation, and may route coolant through otherportions of the thermal support, such as those supporting othercircuitry and components. In the illustrated embodiment, channel 152extends beneath the interface plate 148, adjacent to a lower surface onwhich the energy storage and conditioning circuitry is mounted.

[0073] Features are formed within channel 152 for enhancing the heattransfer from the power electronic circuit. In the embodiment of FIG.14, a diversion plate 154 is secured within the channel for divertingcoolant within the channel. As described in greater detail below,additional heat transfer elements, such as fins or other coolingfeatures may also be positioned within the channel, and may be integralwith or separate from the interface plate 148. As also illustrated inFIG. 14, thermal support 12 may include sealing features to ensureisolation of the coolant from the circuitry mounted thereon. Aperipheral channel 156 is formed in a present embodiment to receive aseal (not shown) fitted between the thermal support 12 and the interfaceplate 148. The seal both promotes isolation of the coolant from thecircuitry, and allows for some degree of differential thermal expansionand contraction between the interface plate 148 and the support 12.Finally, in the illustrated embodiment, a baffle 158 is formed withinchannel 152 to further direct coolant through the channel for heatextraction. As will be appreciated by those skilled in the art, variousalternative configurations, impingement surfaces, and flow ofpath-defining elements may be inserted into the thermal support todefine desired thermal gradients and produce optimum patterns ofturbulence and optimum transitions between turbulent and laminar flowregimes within the support adjacent to the power electronic circuit 14.

[0074] FIGS. 15A-15G illustrate certain exemplary configurations offeatures envisaged for removal of heat via the interface plate 148 andthe thermal support 12. As shown first in FIG. 15A, the interface plate148 may include integral features, such as fins 160, small heat pipes,impingement targets, turbulators. In the present embodiment, plate 148is made of a material dissimilar to that of which the thermal supportitself is comprised. The material may be adapted to the particularelectronics and the methods for processing the electronic devicesubassembly. In a present embodiment, plate 148 is made of aluminumsilicon carbide (AlSiC). A seal 162 is positioned adjacent to theinterface plate 148 and would be received within a groove of the typeillustrated in FIG. 14. Along a lower surface 164 of plate 148, a seriesof fins 160 are formed, such as during a casting operation. The finscould also be added to the plate in an assembly process. The plate alsopresents an upper surface 166 on which the power electronic devicesubassemblies 130 are formed as described in greater detail below.

[0075] Where fins 160 extend from plate 148, various types of fins andpatterns of arrangement may be provided. As illustrated in FIG. 15B, thefins may be formed as pins 160 which extend from the lower surface ofthe plate. Again, any desired form of pin may be provided, such as pinshaving a generally trapezoidal cross section. In the embodiment of FIG.15B, a straight matrix pattern 168 is provided with the pins beingaligned within parallel rows and columns. As illustrated in FIG. 15C,staggered patterns 170 may be provided in which rows or columns of pinsare offset with respect to one another. Moreover, as illustrated in FIG.15D, pins 160 may extend from plate 148, while additional pins or otherthermal transfer features 170 may intermesh with the pins of the plate,and extend from other plates, or from the base of the channel 152 formedwithin the thermal support. The fins, pins, or other thermal conductionextended area enhancements may be staggered in pitch such that whenassembled one on top of the other or when inserted from opposite sidesof the thermal base the patterns inter-mesh to form optimum arrangementand minimum geometry that cannot be achieved effectively by a singlemanufactured piece.

[0076]FIG. 15E illustrates an alternative configuration in which theinterface plate 148 does not include integral thermal transfer features,but wherein a heat dissipation element 174 is assembled between theinterface plate 148 and the base of channel 152. In a presentembodiment, element 174 may include a corrugated or bent-fin structurehaving a 5 plurality of generally parallel sheet-like sections defininga large surface area for heat removal; in addition, many other extendedsurface enhanced configurations can be accommodated by this mechanicalarrangement such as metal foams, metal matrix foams, metal polymermatrix foams, and so forth. As a further alternative configuration, asillustrated in FIG. 15F, thermal transfer features may be formed onadditional elements interfaced with the thermal support. In the exampleof FIG. 15F, power electronic device subassemblies 130 are mounted to apair of plates on either side of the thermal support. In this case, eachof the interface plates includes thermal features which extend intochannel 152 for heat removal. It should be noted that where 2-sidedarrangements are utilized, channel 152 may define an aperture extendingcompletely through the thermal support, or may form two separatechannels with flow paths interconnecting with one another.Alternatively, two completely separate channels may be formed within thesupport. Finally, as noted above, various alternative flow paths may beprovided within the thermal support, as illustrated generally in FIG.15G. Thus, owing to the form of the channel, any diversion plates andbaffles, and the like within the thermal support, a flow path 178 may bedefined which routes coolant in a desired path so as to establish thedesired temperature gradient within the thermal support.

[0077] FIGS. 15H-15R represent additional alternative flow and coolingconfigurations designed to extract heat from the power electronicdevices during operation. As illustrated in FIG. 15H, the thermalsupport 12 may include a diversion plate 154 provided with apertures 155for directing flow. Flow may thus be directed through the diversionplate between a coolant inlet 22 and a coolant outlet 24. As flow isdirected by the diversion plate and through the apertures, it ispermitted to flow adjacent to the interface plate 148, and through oraround a heat dissipation element 174 as shown in FIG. 15I. In thealternative arrangement of FIGS. 15J and 15K, a diversion plate 154 isagain provided with a series of apertures 155. Flow is directed througha coolant inlet 22, around and through the diversion plate, and exitsthrough a return channel 153. As shown in FIG. 15K, the arrangement maymake use of a baffle 158 for defining a passageway between channel 152and channel 153, and for partially partitioning these channels from oneanother. As shown in FIGS. 15L and 15M, in a further alternativearrangement, coolant inlet and outlets may be provided on the same sideof the thermal support 12. Apertures 155 in diversion plate 154 mayprovide for routing coolant upwardly into close contact with interfaceplate 154 for flow through or around a heat dissipation element disposedbetween the pair of channels 152. In FIGS. 15N and 15O a diversion plate154 is again positioned between the interface plate 148 and an internalbaffle 158 to cause flow to rise up above the diversion plate andthrough or around a heat dissipation element. Again, flow is thusdirected adjacent to the interface plate for heat removal. In thealternative of FIGS. 15P and 15Q, apertures 155 are provided in adiversion plate 154 and direct flow from a central channel 152 upwardlyand around heat dissipating fins extending from the interface plate 148as described above. Flow is then directed downwardly and into returnchannels 153 on either side of the central channel 152. Finally, asshown in 15R, a diversion plate may be provided in a constructionsimilar to that described above with reference to FIGS. 15A-15E. In thisembodiment, however, a baffle 158 is provided to define channels 152.Flow is then directed from a coolant inlet 22 upwardly, around thediversion plate, and through heat dissipating elements, such as pins 160and 172 extending from the interface plate 148 and from the diversionplate 154, respectively. Following flow through the circuitous pathdefined by the pins, flow is directed downwardly into the oppositechannel 152 and outwardly through the coolant outlet 24.

[0078] It should be noted that the various alternative configurationsdescribed herein for routing coolant can be subject to wide variationand adaptation depending upon the heat dissipating requirements, theconfiguration of the thermal support, the location and disposition ofthe power electronic circuits, and so forth. The examples provided areintended to be exemplary only.

[0079] As described above, the interface plate 148 may be separatelyfabricated from the body of the thermal support 12. Moreover, thethermal support 12 may incorporate a substantial number of featuresuseful for extracting heat, mechanically mounting the various circuitryand components, establishing an electrical reference plane for thecircuitry, and shielding the surrounding circuitry, at least somewhat,from stray electromagnetic interference generated by operation of thepower electronic devices. The thermal support structure may be formedout of a number of materials and manners (e.g., polymers, polymer matrixcomposites, thermosetting materials and processes, utilizing a number ofnet shape, forming, discrete machining, fixture bonding, and similarProcesses). The number of integrated features that the thermal base mayprovide may be broken into cellular elements that can be included orexcluded by means of settings in the tooling of manufacture so that manypower electronic designs, topologies, and configurations can be built toorder from the core elements embodied in the tooling and design.Moreover, features may be formed on or added to the thermal support forreceiving the interface plate 148 and for defining a volume in which aninsulation or potting material may be deposited. In present embodiments,the thermal support may include a partial integral flange 126 (see,e.g., FIG. 14). In alternative arrangements, a frame 114 may be added tothe thermal support to accomplish certain of the mounting and insulationand potting functions, as illustrated in FIG. 16. In this embodimentalso, however, the thermal support 12 is fabricated separately from theinterface plate 148 to permit any special processing of the circuitrydisposed on the interface plate.

[0080]FIG. 17 illustrates an exemplary interface plate 148 with powerelectronic device subassemblies 130 disposed thereon. As noted above,the interface plate forms a substrate on which the power electronicdevice subassemblies are disposed, and may be made of any suitablematerial. In a present embodiment, however, the plate is made of AlSiC.The material of which the plate is fabricated is preferably at leastpartially thermally matched to the materials utilized for the powerelectronic device subassemblies disposed thereon. Thus, while differentcoefficients of thermal expansion will be anticipated between thematerials, these are preferably kept to a level sufficiently low toreduce stresses between the materials and to prevent or significantlylimit delamination of the materials from one another during their usefullife.

[0081] An exemplary electronic device subassembly is illustrated in FIG.18. As noted above, the electronic device subassembly 130 is placeddirectly on the interface plate 148 to promote good thermal transferfrom the electronics devices to the interface plate. In the embodimentof FIG. 18, a bonding layer 180 is disposed on the plate 148 at a padlocation corresponding to the location of the respective devicesubassembly 130. A substrate 182 is then placed on the bonding layer180. The substrate includes pad locations for mounting the powerelectronic circuits and for interconnecting circuits with externalcircuitry. In the illustrated embodiment, the substrate 182 is a directbond copper or direct bond aluminum substrate including pads for theelectronic devices and pads for wire bonding the interconnectionsbetween the devices and the interfacing circuitry. A ceramic electricalinsulating layer and a metal layer beneath the ceramic layer may beprovided, but are not visible in FIG. 18. Thus, regions of direct bondmaterial 148 are formed directly on the substrate prior to assembly. Atlocations where the electronic devices are to be placed, additionalbonding layers 186 are provided. Bonding layers 186 may be similar tobonding layer 180 interposed between the substrate 182 and the interfaceplate 148. Where desired, sensors may be incorporated into the devicesubassembly, such as a temperature sensor 188 in the embodimentillustrated in FIG. 18. The power electronic devices are then placed onthe bonding layers 186. In the illustrated example, each devicesubassembly 130 forms a portion of an inverter circuit, and thusincludes a solid state switch assembly 190 (such as an IGBT assembly)and a fly-back diode assembly 192. Again, interconnections between theswitch assembly 190 and the diode assembly 192 are made subsequently bywire bonding.

[0082] The device subassembly design illustrated in FIG. 18 providesseveral significant advantages. For example, a grease layer which mightotherwise be employed in such arrangements is eliminated by directbonding of the device subassembly to the interface plate 148. The use ofdirect bond copper or direct bond aluminum for substrate 182 provideshigh voltage insulation, good thermal characteristics, and goodexpansion control during operation of the device. Again, the selectionof the particular materials employed in the device subassemblypreferably provide for reduced differential thermal expansion andcontraction, at least for adjacent components of the device subassembly.Where desired, the material selections may provide for a gradient inthermal expansion and contraction coefficients to further reducestresses.

[0083]FIGS. 19A and 19B illustrate a present embodiment for a terminalstrip used to channel power to and from the power electronic devicesdescribed above. The terminal strip is particularly well-suited for usewith a thermal support of the type illustrated in FIGS. 11-13. Thefeatures of the terminal strip may, however, be incorporated into othertypes of structures within the device, such as the frame 114 illustratedin FIG. 16. The terminal strip 134 includes features designed to serveas terminal or contact points for the conductors described above. Thestrip also provides conductive elements or straps which communicatebetween the power electronics circuitry and energy storage andconditioning circuitry, thereby eliminating the need for a DC bus as inconventional devices. Thus, as illustrated in FIG. 19A, terminals 116are provided for the outgoing power conductors (not shown in FIG. 19A).Terminals 116 are separated from one another and from conductors for theincoming DC power by insulative separator 118. On a back side of theterminal strip 134 a series of connection pads 132 are provided and areintegral with the terminal conductors as described below.

[0084] As shown in FIG. 19B, on a connection side of the terminal strip,terminals include elements designed to interface with conductors for theincoming DC power in the embodiment shown. It should be borne in mind,however, that where other power types and ratings are provided, such asfor incoming and outgoing AC power as in converter circuits, theconfiguration of the terminal strip can be adapted accordingly.

[0085] The terminal strip illustrated in FIGS. 19A and 19B isparticularly well-suited for fabrication via molding operations, beingitself made of an insulative material. The various conductors andconductive elements of the terminal strip may be molded in place withinthe insulative material so as to be easily retained within the materialfor later installation and connection. As shown, in FIG. 19B, powerterminal conductors 194 are embedded within the insulative material ofthe terminal strip for connection to leads or conductors interfacing theterminal strip with outgoing power lines. Additional terminals 196 areprovided for similar leads for coupling the terminal strip to incomingpower conductors. In the embodiment illustrated in FIG. 19B, theterminals 196 are formed as conductive straps which permit connection ofthe incoming power, typically direct current power in an inverterapplication, with elements on both sides of the thermal support asdescribed below. In particular, because in applications requiring energystorage and conditioning circuitry conductive paths may be requiredbetween the power electronic devices and a capacitor bank, thearrangement of FIG. 19B permits such connections to be easily madewithout the need for a DC bus. Accordingly, it has been found that thearrangement reduces the incidence of parasitic inductance within theassembly. In the embodiment of FIG. 19B, similar conductive straps 198are provided at ends of the terminal strip to further facilitateconnection to the power electronic devices as described more fullybelow. The molded (or net shaped) interconnects can be made of variouscombinations of thermally conductive but electrically insulatingmaterials or elements. These may include but are not limited to:thermally conductive polymers, polymer combinations with direct bondcopper, direct bond aluminum, ceramic metal sprayed systems, sheetelectrical insulators, fluid coolant ports and passages, and so forth.By using thermally conductive polymers (which may, however beelectrically insulating) for the support structure of the conductors interminal strip 134, a direct thermal path between the conductors 116 and198 and the thermal support 12 allows for cooling of those conductorsand interconnections with them. This provides a major cooling path forthe conductors and reduces heat flow into any components connected tothem. This also allows for reduced heating of the energy storage andconditioning circuitry package attached to the terminal strip, as wellas any connector circuitry also attached to the terminal strip. Thereduced heating, in turn, promotes greater reliability of the circuitcomponents as well as a higher electrical rating. A further benefit ofthe arrangement is to reduce stress on external, interconnectingcomponents and circuitry.

[0086] As shown in FIG. 20, the arrangement of the terminal strip ofFIGS. 19A and 19B facilitate interconnection of the power electronicdevice subassemblies 130, the energy storage and conditioning circuitry38, and the terminals of the device. In particular, the arrangement ofFIG. 20 provides power electronic device subassemblies 130 arranged in arow of six device subassemblies. In a typical inverter application, twosuch device subassemblies will be associated with each output phase soas to provide positive and negative lobes of a simulated AC waveform. Inthe arrangement shown, first end pads, which may be referred to as DCend pads 200A and 200B, are provided adjacent to each end of theterminal strip. End pads 200A and 200B correspond to the end pads 132adjacent to ends of the terminal strip illustrated in FIG. 19A.Additional pads 202A and 202B are provided spaced from pads 200A and200B at locations corresponding to the incoming power terminals 196(see, e.g., FIG. 19B). Finally, pads 204A, 204B and 204C are provided atlocations corresponding to the outgoing power terminals 194. Pads 200Aand 202B, and pads 200B and 202A are interconnected as illustrated inFIG. 20 so as to electrically couple the pads adjacent to ends of theterminal strip to the pads adjacent to terminals 196 as shown in FIG.20. These same interconnected pads are then electrically coupled to highand low sides of the energy storage and conditioning circuitry 38 asillustrated diagrammatically in FIG. 20. The device subassemblies 130are then electrically coupled to pads 200A, 200B, 202A, 202B, 204A, 204Band 204C as illustrated in FIG. 20 such as by wire bonding connections206. This wire bonding, it will be noted, effectively couples eachdevice subassembly both with a pad electrically coupled to the energystorage and conditioning circuitry 38, and to a pad associated with anoutgoing power terminal 194. Many alternative methods of bonding thedevice subassemblies to the power terminations may be envisioned in thepresent technique; for example: tape bonding, metal braid resistancewelding, brazing, mechanical attachment, laminated thin metal tapes,soldered or brazed metal straps with intrinsic strain relief, flexiblemetal straps with gas tight pressure connections, and so forth. Eachpair of device subassemblies then, defines a portion of the invertercircuit for each phase of outgoing power.

[0087]FIG. 21 illustrates diagrammatically the electrical circuitestablished through the terminal and interconnection arrangement of FIG.20. As shown in FIG. 21, control circuitry 36 is interconnected withdriver circuitry 34 in a typical inverter drive application, such as viainterconnections 40. The driver circuitry 34, which may be mounted onthe same side of the thermal support described above as the powerelectronics devices forming the inverter circuit itself, isinterconnected with the device subassemblies 130 via additional wirebonding 208. Each device subassembly 130, then, is electrically coupledto an output terminal 194 positioned at alternate locations along theterminal strip illustrated in FIGS. 19A and 19B. The devicesubassemblies 130 are also electrically coupled to the incoming powerterminals 196, and circuitry 38 is similarly coupled to the terminalsvia the straps 98 illustrated in FIG. 19B. Also in the exampleillustrated in FIG. 21, sensor circuitry 112 is associated with at leasttwo of the outgoing power lines.

[0088] As noted above, the packaging and configuration of the module 10may be arranged so as to permit incoming power and outgoing power to berouted in a variety of manners depending upon the arrangement ofinterface circuitry and components. The packaging may also permitvarious routing arrangements for coolant. FIGS. 22A-22F illustrateexemplary arrangements for such routing options. As shown in FIG. 22A, afirst configuration 210 corresponds generally to that illustrated inFIG. 8. That is, incoming power conductors 18 are provided along an edge28 of the module, along with outgoing power conductors 20. Incomingcoolant line 22 is provided along an adjacent edge offset from edge 28,along with outgoing coolant line 24. In an alternative configuration 212shown in FIG. 22B, the incoming power conductors 18 and outgoing powerconductors 20 are again provided along edge 28. However, coolant issupplied and returned via a manifold 222 provided along a bottom side224 of the module. In an other alternative configuration 214 shown inFIG. 22C, incoming power conductors 18 enter through a top side 226 ofthe module. Outgoing power conductors 20 are still provided along edge28, and coolant lines 22 and 24 are provided along edge 30. In anotherconfiguration 228 of FIG. 22D, incoming power lines 18 enter throughedge 28, as do outgoing power lines 20. In this embodiment, however,coolant enters through an edge 30 of the module as indicated at line 22,and is extracted from the module along an opposite edge at line 24. Aswill be appreciated by those skilled in the art, such arrangements maybe useful for establishing desired temperature gradients through themodule as defined by coolant flow and the positioning of heat-generatingelements within the assembly. In a further alternative configuration 218shown in 22E, all lines, incoming power 18, outgoing power 20, andcoolant lines 22 and 24, are accessed along edge 28. Thus, arrangement218 of FIG. 22E may facilitate one-sided or plug-in mounting of themodule. As a further example of alternative interconnections, theconfiguration 220 of FIG. 22F provides incoming power lines 18 along atop side of the module. Outgoing power lines 20 are provided along anopposite bottom side. Coolant may be routed through another surface,such as edge 230 as indicated for lines 22 and 24 in FIG. 22F.

[0089] As noted above, various connector configurations can be providedin the present technique for routing power and coolant to and from themodule. FIGS. 23 and 24 illustrate exemplary configurations for plug-inconnections to the module. As illustrated in FIG. 23 where multipleconnections are provided on one surface of the module, a ganged-typeconnector may be employed. A connection interface, designated in FIG. 23by reference numeral 232 may thus include a plurality of conductorsextending from the module 10. In FIG. 23 connectors 106 and 108 have agenerally circular or cylindrical shape. Other forms may, of course, beemployed, such as flat conductors, plate-like conductors, angledconductors, and so forth. The connector interface 232 in FIG. 23 issurrounded by a peripheral flange 234 which serves both to align amating connector 236 and to extend shielding of the conductors beyondthe housing of the module. Accordingly, flange 234 may, where desired,be a metallic extension of the housing. The mating connector 236preferably includes an insulation plate 238 which forms a rear wall ofthe connector and which at least partially surrounds interface sockets240. The housing 242 of the mating connector 236 supports the insulationplate and interface sockets, and interconnections between the socketsand leads 246 are made within the connector. A peripheral wall 244 mayextend around the sockets to provide protection for the sockets,alignment with flange 234 of interface 232, and extension of shieldingto the sockets and connections once made.

[0090] The connections are made to the module, then, by simply pluggingthe mating connector 236 into the interface 232 as indicated by arrow248. As will be appreciated by those skilled in the art, various lockingfeatures, securement features, straps, fasteners, or the like may beprovided to ensure that the connector is fully and securely installed.Moreover, a sensor or switch assembly (not shown) may be provided ineither the connector interface 232 or the mating connector 236 to sensewhether the connection is appropriately completed. Feedback signals fromsuch devices may be used by the controller to prevent or limitapplication of power to the module until appropriate interconnectionsare made.

[0091] In configurations employing more than one entry location forconductors, multiple connectors may be provided as indicated in FIG. 24.The arrangement of FIG. 24 provides two incoming power conductors 106along a top surface of the module, with three outgoing power conductors108 along a bottom surface as in the arrangement of FIG. 22F. As shownin FIG. 24, a first connection with the incoming power conductors fromleads 246 is made at an incoming power connection interface 250. Theincoming power connector 254, in the illustrated embodiment, may includea peripheral flange 244 as in the previous example, with an insulationplate 238 protecting connections between the leads and interfacesockets. The connector 254 is then simply plugged into the incomingpower connector interface 250. Outgoing power connections are made in asimilar manner via an outgoing power connector interface 252. Thisinterface, similarly, is surrounded by a peripheral flange 234. Aconnector 256, similarly surrounded by a peripheral flange 244 andhaving an insulation plate 238, is connected into the outgoing powerconnector interface 252. Again, shielding may be provided at one or bothlocations by the cooperation of the peripheral flanges. Also, securementdevices may be provided at each location to ensure that the connectorsare appropriately made. As in the previous example, sensors or switchesmay be provided in both connectors to ensure that the appropriateconnections are made prior to application of power to the module.

[0092] As mentioned above, various alternative configurations may beenvisaged for the particular external packaging of the module, as wellas for its shielding from stray EMI. FIGS. 25 and 26 illustrateexemplary alternative configurations based upon a drop-in design. Asshown in FIG. 25, an interface plate 258 may be provided, as an example,with interconnections made directly to a rear surface of the interfaceplate. The configuration of the module 10 may generally follow the linesdescribed above including fabrication about a thermal support 12.Coolant conduits 260 may be provided for routing coolant to and from thethermal support. In such cases, the coolant conduits may be routeddirectly through the interface plate 258. A canister-type housing 262(see particularly FIG. 26, is provided which connects to interface plate258 to surround, support and shield the module. Interconnections withthe interface plate may then be made via a ganged-type connector 236 asillustrated in FIG. 26.

[0093] FIGS. 27A-27D represent exemplary techniques for joining thecontacts with terminal strip 134 to circuits formed in the powerelectronic device subassembly 130. In the exemplary embodiment of FIG.27A, stamped or similar contact members 266 are soldered or otherwisebonded to the device subassemblies 130 and extend to the terminal strip148. The connective elements 166 may be soldered, welded, brazed, laseror Ebeam welded, conductively adhesively bonded, or electrically coupledin any other way to the device subassemblies 130 and to the terminalstrip 134. Strain reliefs may be formed within stamped, coined, cut, ormolded conductive elements of this type to provide an optimal sectionfor the transmission of current. In the alternative illustrated in FIG.27B, metal laminates, plastic metal tapes, multiple such tapes,electrical braids, ribbons, and the like, denoted generally by referencenumeral 268 similarly extend between the circuits formed on the devicesubassembly 130 and the terminal strip 134. Electrical contact may alsobe provided via power assembly gas-tight pressure contact structures.Where desired, the separate elements of such tapes, ribbons or braidsmay be joined through a portion or their entire length, such as byresistance welding. In the further alternative illustrated in FIG. 27C,separate contact members 270 and 272 are provided on the devicesubassembly 130 and the terminal strip 134, and are joined to oneanother during assembly of the module. Each of the contact members maybe formed by any appropriate method, such as by stamping or coining, andbonding or otherwise securing the contact members electrically andmechanically to the device subassembly and terminal strip. Finally, asillustrated in FIG. 27D, an extension 274 of a thermally conductivelayer of the device subassemblies themselves may be provided forconnection to the terminal strip 134. For example, in modules employingdirect bond copper or direct bond aluminum, a conductor may be extendedfrom an output terminal to the terminal strip. Stress relief may beprovided as in the aforementioned arrangements, as well as selectivepatterning of the conductive layer of the device subassembly, wheredesired.

[0094] FIGS. 28A-28D illustrate alternative terminal and terminalassembly cooling arrangements. As mentioned above, both incoming andoutgoing current may be passed through terminal strip 134. In use,heating within the terminal strip may occur and may be extracted throughany appropriate arrangement, such as the arrangements illustrated inFIGS. 28A-28D. In a first exemplary arrangement shown in FIG. 28A, theterminal strip comprises one or more sections 276 and 278 which may bemade of a thermally conductive, electrically insulating material thatsurrounds and supports the various conductive elements described aboveof the terminal strip. Examples of such materials might includeceramic-filled thermoplastics or liquid crystal polymers.

[0095] In the arrangement illustrated in FIG. 28B, a manifold 280 isformed for receiving a coolant, such as by interconnection with thecoolant passages formed within the thermal support 12 as describedabove. The manifold serves to feed channels 282 which route coolant intoand out of the terminal strip for cooling purposes. In the arrangementof FIG. 28C, a thermal extension 284 is provided which adds surface areato contact between the thermal support 12 and the terminal. The thermalextension 184 is designed to interface with a corresponding andsimilarly formed recess or groove 286 formed within the terminal strip134. As will be appreciated by those skilled in the art, any suitableconfiguration or cross-sectional shape for the extension and recess maybe provided. Similarly, as shown in FIG. 28D, an extension 288 may beformed in the terminal strip 134 and designed to interface with acorresponding groove or recess 290 formed within a portion of thethermal support 12.

[0096]FIGS. 29A and 29B represent alternative configurations forterminal plugs and connections useful in the various connectionconfigurations described above. As shown in FIG. 29A, housing 94 isdesigned to surround conductor 108, while conductor 108 receives leadconductor 246 when the connector is made up. Housing 242 is provided onthe mating connector 236 and at least partially surrounds the leadconductor 246. An electrically insulating body 292 is provided withinthe housing 94 around the conductor 108. A wire shield and groundconnection 294 is provided within the housing 242, while an insulatingmember 295 is provided between the connection 294 and the lead conductor246. The resulting assembly provides for both a good electricalconnection of the conductor of the module and the mating connector, aswell as the offering EMI shielding and continuity of shielding betweenthe connector and the module. FIG. 29B represents a similar arrangement,but wherein a conductive receptacle shell 298 is formed to interfacewith the flange 244 of the connector housing 242.

[0097] FIGS. 30A-30C illustrate alternative power device substratemounting and heat exchanging configuration for use in a module of thetype described above. In the embodiment of FIG. 30A, an interface 300 isprovided as described above for transmitting thermal energy from thepower electronic device subassembly 130 through the interface plate 148.As shown in FIG. 30B, various arrangements may be provided forinstalling two or more power electronic device subassemblies 130 on acommon thermal support 12. For example, two such arrangements areillustrated in FIG. 30B, including channels 152 for conveying coolingfluid through the support. In one exemplary configuration, pins 160extend from an interface plate 148 and are cooled by fluid flowingthrough one of the channels 152. In another exemplary configurationshown in FIG. 30B, a heat dissipation element 174 is disposed in achannel for similarly removing heat. The plate 148 may be attached byany suitable method, such as soldering, brazing, welding, or viaadhesive and gaskets to provide adequate sealing. The heat exchangerbase module defined by the support may be made of any conductive metalor polymer or can be made of a variety of non-conductive materials suchas thermoplastics, thermoset plastics, epoxy cast structures, and soforth. Also shown in FIG. 30B, an insert molded seal flange 302 may beprovided for enhancing the seal between the interface plate and thethermal support 12. Such seal flanges may be made by any suitableprocess, such as injection, compression, casting, vacuum casting,adhesive attachment, and so forth. The flange may be bonded duringmolding or as a secondary step into the thermal base, such as at anedge, flange or lip so as to seal against the opening provided in thethermal support for this purpose. As shown in FIG. 30C, a speciallyadapted interface surface 304 may be provided for receiving a devicesubassembly and interface plate assembly. Where provided, pins 160 orsimilar heat dissipation elements may extend through especially providedapertures 306 within the thermal support. Again, a sealing element 162may be provided around the interface plate for sealing against thethermal support.

[0098]FIGS. 31A and 31B represent exemplary configurations for a lowinductance shield and ground arrangement for use in a module of the typedescribed above. In the arrangement shown in FIG. 31A, a thermal support12 includes a partial peripheral flange 126 as described above. Lowinductance paths for metal shielding may be formed as indicated atreference numerals 310, 312 and 314, with the paths 310 being providedon a cover 308 designed to be fitted to the thermal support. The groundpaths may be made of any suitable material, such as metallized polymersor may comprise metal or other conductive elements molded into polymericmaterials at specific locations as desired. The paths may be definedfrom intrinsic thinning of metal sections of castings and by shapingcontact areas for low inductance. Moreover, the paths may bespecifically shaped to provide high frequency power ground contacts, andthe paths may be brought into areas adjacent to the switch substrates.Laminated bus sections 311 may be provided that defines connectionsbetween the high frequency capable conduction paths. Bonding tabs 313may provide for connection between the bus and the device substrates.Through the use of such shielding approaches, the shell or housing forthe overall module may be made of metals, plastics (includingthermoplastics), or any other suitable material or combination ofmaterials.

[0099]FIG. 31B illustrates the power electronic device subassemblies 130disposed within an exemplary arrangement of the type shown in FIG. 31A.The cover 308, which acts as an EMI shield plate is placed over thesubassemblies, which constitutes combined gate driver circuitry andcontrol board circuitry in the illustrated embodiment. Mechanicalconnection and electrical paths are defined by fasteners used to securethe cover to the support 12.

[0100]FIGS. 32A and 32B, and FIG. 33 illustrate alternative exemplaryconfigurations for plug-in modules in arrangements accommodated bybackplane configurations. As shown in FIG. 32A, modules comprised ofthermal supports 12 and power electronic device subassemblies 130 arecoupled to terminal strips 134, with conductors 108 being electricallycoupled to parallel backplane conductors represented generally atreference numeral 322. The backplane conductors may route power to andfrom the modules once these are plugged into or otherwise coupled to thebackplane. The backplane represented generally by reference numeral 318in FIG. 32A, may also provide for connections to coolant streams. In theembodiment illustrated in FIG. 32A, for example, a coolant backplaneconnection adapter 326 serves to interface the inlet and outlet ports ofthe thermal supports with coolant supply lines 324 provided in thebackplane. The individual modules, then, may be plugged into thebackplane and connected for independent or joint operation in a largersystem. An exemplary physical implementation of a modular unit for suchbackplane configurations is shown in FIG. 32B, based generally upon thearrangement shown in FIG. 25. Handles may be provided on the package forfacilitating insertion and removal, while connections may be provided ona single side for completing all necessary interconnects to externalcircuitry. Moreover, sealed coolant conduits may be provided forinterconnecting to the coolant supply lines of the backplane. Theconnections may be extended at different lengths or designed inalternative manners, such as to ensure making or breaking of certainconnections before or after others during installation or removal. Thesemight include, but are not limited to, ultra-fast turnoff and ultra-fast“crowbar” function.

[0101] In the embodiment illustrated in FIG. 33, three such modules areprovided in a similar arrangement and are similarly coupled to thebackplane conductors 322 and coolant supply lines 324. However, as shownin FIG. 33, fluid connections may also be provided between the modulesas represented at reference numeral 330 to facilitate parallel or seriesflow of coolant among the various modules mounted on the backplane.

[0102] To enhance thermal control in modules of the type describedabove, various fluid flow controls may be incorporated into thestructures as illustrated generally in FIG. 34. The flow control system,indicated generally by reference numeral 332, may include varioussensors 334 which detect local temperatures at various locations aroundthe power electronic device subassembly 130 and at other locations inthe system. Input lines 336 feed signals representative of thetemperatures to a flow control circuit 338. The flow control circuit 338regulates the flow of coolant to and from the module via a flow controlvalve 340 coupled to the flow control circuit via an output line 342.Thus, closed-loop temperature control may be provided in the module soas to optimize coolant flow and to minimize variations in thermalcycling, thereby enhancing the life of the power electronic componentswithin the device subassembly 130.

[0103] As noted above, a wide range of circuits may be accommodated thatmay benefit from the various configurations described above. Inparticular, as mentioned above, various types of converter circuits maybe supported on the thermal support and connected, cooled, shielded andso forth as described. FIGS. 35A-35C illustrate exemplary configurationsfor circuitry which may define AC-AC converters, voltage sourceconverters, synchronous rectifiers and similar topologies. In FIG. 35A,a device subassembly 130 comprises a series of solid state switches anddiodes coupled to a DC source in half bridges. The individualsubassemblies 130 are mounted on a thermal support 12 as describedabove, and as shown in FIG. 35B. Electrically, the subassemblies 130 maybe connected to circuitry for producing controlled AC output signals, asillustrated in FIG. 35C.

[0104] Also as noted above, another type of circuitry which may beaccommodated in the arrangements described are AC-AC converters, matrixswitch topologies of the type illustrated in FIGS. 36A-36C. As shown, insuch topologies each device subassembly includes a pair of switch anddiode sets coupled to an AC power source. FIG. 36B illustrates a threephase implementation of such subassemblies mounted to a thermal support12 as described above. An input bus and an output bus are coupled to thesubassemblies for routing of input and output power signals. As shown inFIG. 36C, in the three phase implementation, phase inputs and outputsare electrically coupled to the subassemblies to produce the desiredpower output.

[0105] It should be noted that, while certain three-phase topologies arediscussed herein, the present technique may extend to single phase andother arrangements. Such arrangements may accommodate applications suchas mid-frequency welding applications. Such applications may incorporatea high frequency transformer rather than certain of the capacitorsdisposed on the thermal support. The circuitry supported on andthermally serviced by the support then becomes somewhat modular betweenapplication-specific designs.

[0106]FIG. 37 illustrates an exemplary circuit for one such application,in this case a mid-frequency welding implementation. As will beappreciated by those skilled in the art, in such applications, circuits130 include pairs of solid state switches and diodes. The circuits arecoupled through sources of power by the intermediary of transformers.Additional transformers are provided for output, such to a welding head.As in the previous examples, both the circuits and the energy storageand transforming circuitry may be supported and cooled by the thermalsupport and related techniques described above.

[0107]FIGS. 38A and 38B represent further alternative configurations inwhich cooling may be provided at locations removed from the thermalsupport itself. As shown in FIG. 38A thermal support 12 supportscircuitry within a peripheral flange 126 as described above. Circuitrymay be mounted to both sides of the thermal support 12 as previouslydescribed. Moreover, a cover 308 is provided, such as for providing theEMI shielding as described above. In the embodiment illustrated in FIG.38A, a circuit board is mounted outside the primary cavity in whichother circuitry is mounted. In the illustrated embodiment, the circuitboard comprises a control circuit board 36. Because the coolingrequirements of certain of the circuitry, such as the control circuitboard 36, may be less stringent than those of the other circuitry, suchcomponents may be mounted remote from the thermal support 12. However,additional cooling for such circuitry can nevertheless be provided, suchas the heat pipes of the type illustrated in FIG. 38A and designatedgenerally by the reference numeral 344. As will be appreciated by thoseskilled in the art, such heat pipes will typically comprise thermallyconductive materials which are extended into contact with the inletand/or outlet of the coolant stream. Conduction of heat along the heatpipe 344 then permits removal of heat from the circuitry mounted onboard 36. FIG. 38B illustrates the same arrangement following assembly.An appropriate jumper cable 346 may be provided for channeling signalsand power to and from the circuit board 36.

[0108] While the invention may be susceptible to various modificationsand alternative forms, specific embodiments have been shown in thedrawings and have been described in detail herein by way of exampleonly. However, it should be understood that the invention is notintended to be limited to the particular forms disclosed. Rather, theinvention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention as defined by thefollowing appended claims.

What is claimed is:
 1. A modular power converter comprising: a thermalsupport at least partially defining an electric reference plane andconfigured to receive and circulate a coolant stream for extraction ofheat; an interface plate secured to the thermal support and contactingthe coolant stream during operation; at least one power electronicdevice subassembly disposed on the interface plate and comprising apower electronic device and contact pads for transmitting signals to andfrom the power electronics device, the interface plate and theelectronics device subassembly being at least partially thermallymatched to create a desired thermal gradient to remove heat from thepower electronics device during operation via the substrate and thethermal support.
 2. The modular power converter of claim 1, wherein theinterface plate and the thermal support are made of different materials.3. The modular power converter of claim 1, wherein the power electronicsdevice is formed of a plurality overposed layers including a solid stateswitch, interfaces between the layers being thermally matched to limitthe differential expansion during operation of the solid state switch.4. The modular power converter of claim 3, wherein the overposed layersinclude a substrate on which the solid state switch is disposed.
 5. Themodular power converter of claim 1, wherein the interface plate consistsessentially of AlSiC.
 6. The modular power converter of claim 3, whereinthe layers include a substrate layer bonded to the interface plate, thesolid state switch being disposed on the substrate layer.
 7. The modularpower converter of claim 6, wherein the substrate layer comprisesceramic layer direct bonded to an aluminum layer.
 8. The modular powerconverter of claim 6, wherein the substrate layer comprises a ceramiclayer direct bonded to a copper layer.
 9. The modular power converter ofclaim 1, wherein the power electronics device is part of a subassemblyjoined to the support and interfacing directly with the internal fluidconduit.
 10. The modular power converter of claim 9, wherein thesubassembly is joined to the support by welding.
 11. The modular powerconverter of claim 9, wherein the subassembly is removably joined to thesupport by mechanical fastening means and is sealed to the support. 12.The modular power converter of claim 1, wherein the power electronicsdevice includes a plurality of bonding layers thermally matched toadjacent device layers to reduce differential thermal expansion duringoperation.
 13. A modular power converter comprising: a thermal supportat least partially defining an electric reference plane and configuredto receive and circulate a coolant stream for extraction of heat; aninterface plate secured to the thermal support and contacting thecoolant stream during operation; at least one power electronic devicesubassembly disposed on the interface plate and comprising a powerelectronic device and contact pads for transmitting signals to and fromthe power electronics device, the interface plate and the electronicsdevice subassembly being at least partially thermally matched to createa desired thermal gradient to remove heat from the power electronicsdevice during operation via the substrate and the thermal support;wherein the interface plate and the thermal support are made ofdifferent materials.
 14. The modular power converter of claim 13,wherein the thermal support is a single-piece support.
 15. The modularpower converter of claim 13, wherein the thermal support is amulti-piece support.
 16. The modular power converter of claim 13,wherein the thermal support includes at least one extension forsupporting and cooling additional circuitry.
 17. The modular powerconverter of claim 13, wherein the power electronics circuits form auni-directional power converter.
 18. The modular power converter ofclaim 13, wherein the power electronics circuits form a bi-directionalpower converter.
 19. A modular power converter comprising: a controlledpower electronics circuit including solid state switches configured toconvert incoming power to controlled outgoing power; and a fluid cooledsupport on which the power electronics circuit is directly secured, thefluid cooled support including inlet and outlet ports for a coolingfluid and an internal fluid conduit for directing flow of cooling fluidadjacent to the power electronics circuit for removal of heat therefrom,the support further including an interface plate on which the powerelectronics circuit is secured and which contacts the cooling fluidduring operation, interfaces between the power electronics circuit andand the interface plate being thermally matched to limit differentialthermal expansion during operation of the solid state switches.
 20. Themodular power converter of claim 19, wherein the power electronicscircuit is formed of a plurality overposed layers, interfaces betweenthe layers being thermally matched so limit the differential expansionduring operation of the solid state switches.
 21. The modular powerconverter of claim 19, wherein the overposed layers include a substrateon which the solid state switches are disposed.
 22. The modular powerconverter of claim 19, wherein the interface plate consists essentiallyof AlSiC.
 23. The modular power converter of claim 21, wherein thelayers include a substrate layer bonded to the interface plate, thesolid state switches being disposed on the substrate layer.
 24. Themodular power converter of claim 23, wherein the substrate layercomprises ceramic layer direct bonded to an aluminum layer.
 25. Themodular power converter of claim 23, wherein the substrate layercomprises a ceramic layer direct bonded to a copper layer.
 26. Themodular power converter of claim 19, wherein the power electronicscircuit is part of a subassembly joined to the support and interfacingdirectly with the internal fluid conduit.
 27. The modular powerconverter of claim 26, wherein the subassembly is joined to the supportby welding.
 28. The modular power converter of claim 26, wherein thesubassembly is removably joined to the support by mechanical fasteningmeans and is sealed to the support.
 29. The modular power converter ofclaim 19, wherein the power electronics circuit includes a plurality ofbonding layers thermally matched to adjacent device layers to reducedifferential thermal expansion during operation.
 30. A modular powerconverter comprising: a plurality of controlled power electronicscircuits including solid state switches configured to convert incomingpower to controlled outgoing power; and a fluid cooled support on whichthe power electronics circuits are directly secured, the fluid cooledsupport including inlet and outlet ports for a cooling fluid and aninternal fluid conduit for directing flow of cooling fluid adjacent tothe power electronics circuit for removal of heat therefrom, the supportfurther including an interface plate on which the power electronicscircuit is secured and which contacts the cooling fluid duringoperation, interfaces between the power electronics circuit and theinterface plate being thermally matched to limit differential thermalexpansion during operation of the solid state switches.
 31. The modularpower converter of claim 30, wherein the power electronics circuits aresecured to a single side of the support.
 32. The modular power converterof claim 30, wherein the power electronics circuits are secured tomultiple sides of the support.
 33. A modular power converter comprising:a plurality of controlled power electronics circuits including solidstate switches configured to convert incoming power to controlledoutgoing power, each circuit including a first bonding layer thermallymatched to an underlying interface plate, a substrate disposed on thefirst bonding layer and thermally matched to the first bonding layer, asecond bonding layer disposed on the substrate and thermally matched tothe substrate, and a device layer disposed on the second bonding layerand thermally matched to the second bonding layer; and a fluid cooledsupport on which the power electronics circuits are directly secured,the fluid cooled support including inlet and outlet ports for a coolingfluid and an internal fluid conduit for directing flow of cooling towardthe interface plate for removal of heat therefrom during operation ofthe solid state switches.
 34. The modular power converter of claim 33,wherein the interface plate consists essentially of AlSiC.
 35. Themodular power converter of claim 33, wherein the substrate comprisesceramic layer direct bonded to an aluminum layer.
 36. The modular powerconverter of claim 33, wherein the substrate comprises a ceramic layerdirect bonded to a copper layer.
 37. The modular power converter ofclaim 33, wherein the power electronics circuits comprise at least onesubassembly joined to the support and interfacing directly with theinternal fluid conduit.
 38. The modular power converter of claim 37,wherein the subassembly is joined to the support by welding.
 39. Themodular power converter of claim 37, wherein the subassembly isremovably joined to the support by mechanical fastening means and issealed to the support.
 40. The modular power converter of claim 37,wherein the power electronics circuits comprise a plurality ofsubassemblies.
 41. The modular power converter of claim 40, wherein thesubassemblies are secured to at least two different sides of thesupport.